Extension cost per m² in Newcastle
Extension cost by size in Newcastle
Each row multiplies the current £1,800–£3,000 per m² national benchmark by floor area and then applies the same North East factor.
What can change a real Newcastle quote?
- Floor area and number of storeys
- London and regional labour rates
- Steelwork and structural changes
- Kitchen or bathroom installation
- Glazing and door specification
- Finish level, access and contingency
Local planning considerations
The broad regional factor is useful for planning, but site access, specialist trades and project scale can materially change a Newcastle quotation.
- Exterior, roof and masonry projects should be scoped for the actual exposure and condition of the property rather than a city-wide assumption.
- Older housing can require additional investigation before rewiring, damp treatment or structural alterations are fully defined.
- Access equipment, waste handling and specialist-trade availability should be shown separately in larger project quotes.
How the regional model works
The 0.90× factor places this planning estimate 10% below the national planning baseline. We keep that modelling assumption separate from the dated national benchmark so users can see exactly which part comes from an external source and which part is UK Home Costs modelling.
Sources
House Extension: Cost Breakdown 2026
Published / checked: June 2026
Used for: Extension cost-per-m² benchmarks and common add-on costs
Construction output price indices
Published / checked: 13 August 2026
Used for: Construction price trend and update checks
Frequently asked questions
How much does a house extension cost in Newcastle in 2026?
Our modelled Newcastle planning rate is about £1,600–£2,700 / m², based on the current national £1,800–£3,000 per m² benchmark and the North East regional factor. This is not an observed city-wide quote average.
How much is a 20m² extension in Newcastle?
Applying the same regional model to the current national benchmark gives about £32,400–£54,000 before VAT for a straight-line 20m² example. Structural work, glazing, kitchens, bathrooms and access can move a real quote outside that range.
Why is the Newcastle estimate different from the UK benchmark?
UK Home Costs applies a 0.90× North East planning factor, which places the model 10% below the national planning baseline. The factor is our modelling assumption rather than an external city price index.
Does the extension figure include VAT and professional fees?
The national benchmark used here is stated before VAT. Do not assume architect, structural engineer, planning, building-control, party-wall or specialist survey fees are included unless a contractor quote says so explicitly.